为什么我的主程序默认为除外？

Question

您是否可以检查我的语法并告诉我为什么调试器会跳过$BookingDetail = json_decode($new_string, true); //true param gets assoc array 语句并跳到try。

except上课：

book

class book(object): def _init_(self, title, author, numPages): if title is None: raise ValueError("invalid 'title' argument. please try again") if author is None: raise ValueError("invalid 'author' argument. please try again") if numPages <= 0: raise ValueError("invalid 'numPages' arguement. please try again") self.title = title self.author = author self.numPages = numPages 上课：

main

Answer 1

至少有2个错误：

1. 构造函数被称为__init__，因为jonsharpe已经提到过

2. 您需要str()来连接整数和字符串。所以你需要修改你的打印功能：

   print (b.author + ": " + b.title + "\n" +" Number of page: " + str(b.numPages) )